Fatty Acid Profiles of <i>Erwinia amylovora</i> as Influenced by Growth Medium, Physiological Age and Experimental Conditions

Abstract

Abstract Total cellular fatty acids for 20 strains of Erwinia amylovora grown on trypticase soy agar (TSA) for 3 days at 27°C, and for 3 strains grown on nutrient agar (NA), King's B (KB), glucoseyeast extract carbonate (GYCA) and TSA for 1, 3 and 6 days were analyzed by gas‐liquid chromatography. Forty one percent of total fatty acids were saturated even‐carbon straight chains, 6 % were saturated odd‐carbon chains, 34 % unsaturated acids, 6 % hydroxy‐substituted acids, 1 % branched chains, 7 % cyclic acids, and 4 % unidentified components. Composition was affected by growth medium, physiological age of cells, and chromatograph sensitivity. On TSA and NA saturated odd‐carbon and cyclic acids of the 3 strains (combining 1, 3 and 6‐day data) were higher than on KB and GYCA. Cyclic acids increased with physiological age on GYCA and KB medium. Even‐carbon straight chain and unsaturated fatty acids (major components) constituted a significantly lower percentage of total fatty acids in chromatograms of high sensitivity (30–50 components) than of low instrument sensitivity (15–20 components).